Field of the Invention
This invention relates to a multi-layer wiring board having a plurality of printed wiring bases stacked therein via an adhesive layer, and a method of manufacturing the same.
Description of the Prior Art
Known, among wiring boards of a multi-layer structure having a plurality of printed wiring bases stacked therein via an adhesive layer, as a component built-in board having, for example, an electronic component such as a semiconductor component, or the like, built in thereto, is the electronic device utilizing a multi-layer printed wiring board disclosed in Japanese Unexamined Patent Application Publication No. 2007-80857 A. This electronic device comprises a multi-layer structure in which an electronic component is built in between printed wiring boards, and comprises characteristics of having a certain degree of flexibility and at the same time securing an arbitrary layer spacing while advancing film-thinning.
However, in the above-described electronic device of conventional technology disclosed in Japanese Unexamined Patent Application Publication No. 2007-80857 A, the more film-thinning is advanced, the greater the occurrence of various kinds of problems such as a kink depending on mechanical strength or flexibility of the wiring board in each layer, hence further improvement in mechanical strength and flexibility accompanying the film-thinning is required.